We’ve known for a while that Fox and Marvel Studios were talking about buying the Marvel Fox characters and more. This would include the X-Men, Fantastic Four, and Deadpool. Now, people are stoked to see these characters in the MCU, but how could they do this?
Be warned in case any of these theories are true and end up ruining your life.
Reboot the Fox Marvel Characters

Most likely, this will happen with all the fox characters. They’ll probably all be rebooted for the MCU franchise. If they don’t than it’s going to cause a lot of problems because the X-Men timeline is crazy messed up. The timeline began to fall apart when X-Men: Days of Future Past arrived. Also all the origin stories came. The timeline for these movies fell apart. Most likely, they’ll reboot the franchise. With that in mind, let’s start.
The Multiverse Theory
My, first theory on how Marvel Studios could introduce these characters is through the multiverse. We know that through Doctor Strange and Spider-Man: Into the Spider-Verse, that the multiverse does exist in the MCU. I think, after all that has happened in the MCU so far, that the most plausible way to introduce the X-Men and mutants, is through the multiverse.

Maybe Doctor Strange finds a way to travel between dimensions, and he finds the X-Men. Maybe, the Tesseract can open gate ways into other dimensions. We don’t know, but I think it’s a very smart and easy way to introduced all those mutants.
One interesting thing to think about, is if this is true, than there could be another Thanos and infinity stones in that universe. Just a thought.
Not Only the X-Men

Now, this is mainly talking about the mutants and X-Men. The Fantastic Four, I believe, could be introduced into the MCU much easier.
Fantastic Four got their powers through failed laboratory experiments. This means you could introduced four new superheroes much easier than an entire race of mutants into the MCU. I think that the Fantastic Four and Deadpool are the easiest characters to introduced into the MCU.
Yes, we know that Deadpool is a mutant, but he got his powers different than the rest. He got them the same way Scarlet Witch got hers: through experiments. It’s a lot easier to bring a few characters into the MCU, than an entire race.
Now, I’m dying to see Wolverine introduced into the MCU. I’ve been waiting for a Wolverine vs Hulk movie FOREVER! I would love to see him introduced into the MCU. I think Fantastic Four and Deadpool would also be great characters to introduce as well.
How Would Deadpool Work

In my personal opinion, I don’t think anyone is going to be a better Deadpool, than Ryan Reynolds. I think he’s by far, the best actor for that role. If Disney were to introduce Deadpool into the MCU, would Ryan Reynolds still play the character? Would Disney want someone else to play the character?
ALSO…will they keep the Deadpool movies, rated R? Having Deadpool curse every ten seconds and making references to other movies, is why we love him so much. Will Disney take away Deadpool breaking the fourth wall, and act like he doesn’t know if he’s in a movie? We don’t know, and it won’t know until the deal is finalized.
This probably won’t happen until around March, which isn’t to far away know.
Conclusion
How will Disney do all this? Who knows, but I can’t wait to see how they do it. Last I checked, Disney is paying around $52 billion dollars for all these movie rights and more. Who knows what they’re going to do with all of them, but if they get all this amazing content, than all we need now is the Spider-Man rights from Sony, and Marvel should own everything.
Only time will tell us these mind bending questions. Until next time!